Enabling a sense of presence in Virtual Reality

Virtual Reality has emerged from the ashes of the early 90’s as a potential technology to revolutionise our everyday lives. However, some major challenges still exist, both technical and aesthetic, before this can happen. In a series of short blog posts I will examine the major flaws preventing VR from becoming a mainstream technology and propose possible solutions. Let us start with the technical restriction of replicating realistic movement and sense of presence.

Locomotion

Currently, the majority of VR experiences/ games offer the user a seated experience where their movement is controlled with a gamepad, this can often lead to a disconnect between the users body and the movement viewed on the VR headset. In turn, this can contribute to a lack of presence in the game space but perhaps more importantly can lead to feelings of nausea. The HTC Vive looks to overcome this problem by using room scale experiences that at least provide the user with the ability to walk around small areas. Multi-directional treadmills can also provide realistic walking simulation although they work by canceling the user’s motion to mimic acceleration (equivalent to walking on slippery ice) so there is a mismatch as the body attempts to translate this new movement through muscle memory into one it has become accustomed to for years (walking).

But what happens when you are in a VR experience that has a bigger footprint? In order to explore truly realistic VR on foot such as large buildings or even cities this can create a major issue. Teleporting or returning to a controller can provide a lightweight solution but totally shatters any immersion and your mind becomes immediately disengaged. Redirected walking is a method used by developers to trick the mind into thinking they are walking in a straight line when in fact they are slightly moving on a curved/different path in the real world. This enables up to a 26% gain or 14% loss in distance travelled or 49% gain or 20% loss in rotation (yaw) without user detection. The body perceives the movement in a certain direction but without visual cues is less accurate when it comes to measuring the distance/ rotation travelled. So we are essentially hacking our brain and exploiting loopholes in our circuitry.

The paper Estimation of Detection Thresholds for Redirected Walking Techniques posits that a technique called curvature gain can allow the user to walk in a 22 metre circle in a real room while travelling in a straight line in the virtual world. This can open up huge opportunities for expanding the virtual environment that was previously impossible while retaining the sense of locomotion felt by the user.

Haptic response

Kevin Kelly, founder of Wired magazine commented that “we are moving from an internet of information to an internet of experiences”. VR can also include other physical stimuli through passive haptic feedback where physical objects are linked to visual cues in the virtual world such as a torch or sword. They can be further enhanced by adding other sensory properties such as temperature or texture. However, this is not scalable as for every virtual prop, a physical equivalent needs to be created.

Remarkably, a method called Redirected touching can provide a solution where a real object is placed in the physical environment and remapped in the virtual space to assume several different shapes. This is achieved by using a discrepancy in hand interaction between the real and virtual, evident in the example below. Again, the visual reference tricks the user into believing that the physical object has many more sides than it actually does.

Taking this one stage further TheVoid has set up situated installations (think Laser Quest with VR) ranging from ancient temples to futuristic alien worlds where the physical environments are augmented in VR with digital equivalents. At one point you noticeably feel the change moving from a research laboratory corridor indoors to a suspended walkway outdoors, feeling the breeze as you move along hundreds of feet above the ground, creating an presence that is hard to imagine. The lack of photorealistic graphics does not detract from the user having a heightened sense of agency facilitated by peripheral stimuli and the ability to interact and touch all the environments.

Of course, this particular setup is not scalable at the moment but you start to understand how by melding additional sensory elements to VR, immersion can be enhanced leading to a more convincing proposition. VR is by no means the finished article yet but the myriad of speed bumps that block its path to mainstream adoption are slowly being eroded by the ability to employ mind hacks, utilising innovative techniques to trick the user into a greater sense of presence.